DESCRIPTION (Adapted from Investigators' Abstract): The long-term goal of this project is the complete characterization of a portion of human chromosome 8, at the molecular level. This will be accomplished using a strategy that progressively narrows the focus of the work to smaller regions of the chromosome while increasing the level of detail at which each region is analyzed. The first specific aim of this project is to construct a panel of human/hamster hybrid cells, starting with human cells carrying deletions on chromosome 8 derived from patients with Langer- Giedion syndrome and other deletion syndromes. This panel will be used to map a collection of chromosome 8 specific DNA probes to regions of the chromosome defined by the deletion of chromosome 8 specific DNA probes to regions of the chromosome defined by the deletion endpoints. The hybrid cell panel and the collection of mapped probes will be important resources for any investigators mapping genes on chromosome 8. The remainder of this project will focus in on chromosomal band 8q24.1, a region of 10 to 15 million base pairs which includes the deletion endpoints from most of the Langer-Giedion patients. The probes mapped to this region will be used in conjunction with the technique of pulsed field gel electrophoresis (PFGE) to construct a large-scale restriction map. The probes will also be used to characterize reduced-complexity hybrids carrying single, small fragments of chromosome 8. A subchromosomal library will be produced from one of the reduced complexity hybrids, and will be used in conjunction with yeast artificial chromosome (YAC) clones from a total human library in the construction of an overlapping clone map of the 8q24.1 region. The end result of this project will be to make a significant portion of a human chromosome available for further study at the molecular level.